I know this is really boring but I really need help to find sandals that fit quite specific criteria. If anyone can point me in the right direction to the following I'd be eternally grateful: supportive sole like birkenstocks but not as flat, not toe-post, not sling back (so just slip on), flat but not mega flat as that hurts my back and not ugly. I've had fit-flops in the past which were comfortable but I've gone off the style of them. Oh and online too as obvs can't go shopping. Thanks!